BfR-Wissenschaft 
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Table 7.2: Components of COREXIT© 9500 and COREXIT© 9527 
Chemical name 
Hazard classification accord 
ing to GHS (UN 2013) # 
Hazard 
1,2-Propanediol 
(propylene glycol) 
Acute Tox. 4 
low-moderately toxic 
2-Butoxy-ethanoP 
Acute Tox. 4, Skin Irrlt. 2 
Eye Irrlt. 2 
low-moderately toxic 
causes eye and skin Irritation 
Dioctyl sodium sulfosucclnate 
(DOSS 
Skin Irrlt. 2, Eye Dam. 1 
causes eye damage and skin Irritation 
Span 80, Sorbltan, mono-(9Z)-9- 
octadecenoate 
Eye Irrlt. 2 
causes eye Irritation 
Tween 80, Sorbltan, mono-(9Z)-9- 
octadecenoate, poly(oxy-1,2- 
ethanedlyl) derlvs. 
Not classified 
non-toxic 
Tween 85, Sorbltan, trl-(9Z)-9- 
octadecenoate, poly(oxy-1,2- 
ethanedlyl) derlvs 
Eye Irrlt. 2 
causes eye Irritation 
1 -(2-butoxy-1 -methylethoxy)- 2- 
Propanol 
(dlpropylene glycol monobutyl ether) 
Eye Irrlt. 2 
causes eye Irritation 
Distillates (petroleum) 
Asp. Tox. 1 
aspiration toxicity (may be fatal If swal 
lowed and enters airways) 
*Note: This chemical component (Ethanol, 2-butoxy-) is not included in the composition of COREXIT 9500 
#Note: GHS Classification and Labelling according C&L Inventory database of ECHA showing classification by industry as 
well as legally binding classifications fhttp://echa.europa.eu/information-on-chemicals/cl-inventorv-database’) 
Several animal studies on toxicity endpoints were conducted after the Deepwater Horizon oil 
spill. No signs of lung inflammation or lung injury were reported after acute and short-time 
repeated inhalation exposure to COREXIT© EC9500A to rats (Roberts et al 2011, 2014). 
However, breathing difficulties were observed in rats. The findings suggest that the inhalation 
of COREXIT© in sufficient concentrations may lead to the formation of precipitates in the 
airway surface liquid (Roberts et al., 2011). COREXIT© EC9500A did cause transient chro 
notropic effects on cardiac function (Roberts et al. 2014). The respiratory and the cardiac 
effects were transient. Sriram et al. (2011) observed neurotoxic effects in rats. The findings 
are suggestive of disruptions in olfactory signal transduction, in axonal function, and in syn 
aptic vesicle fusion. All events potentially result in an imbalance in neurotransmitter signal 
ling. Whether such acute molecular aberrations might produce chronic neurological effects 
remains to be ascertained. 
The animal studies may show probable target effects but information about chronic effects 
after long-term exposure is missing as well as effects after exposure to oil-dispersant mix 
tures. 
Expected Influence of Dispersant Use 
Apart from direct effects dispersants may also modify the physical properties of the mineral 
oil constituents or their toxicokinetic or toxicodynamic mechanisms in the human body. La 
boratory investigations showed a change of the composition of the water accommodated 
fraction (WAF) of oil-dispersant mixtures compared to the WAF of oil itself (Major et al. 
2012). Depending on the used COREXIT© formula differences in the composition of the 
WAF of the oil-dispersant mixtures were detected. In particular, low molecular weight (MW) 
alkanes and benzene derivatives were identified in the WAF-oil / COREXIT© 9500, whereas 
the WAF-oil / COREXIT© 9527 sample contained a variety of high MW alkanes and polycy 
clic aromatic hydrocarbon (PAH) derivatives (Major et al. 2012). Without dispersant use, a 
quick evaporation of those substances close to the spill site but no persistence of those frac 
tions in the water column would be expected.